[generators] Implement %GeneratorGetSourcePosition.

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index fac56495a0048ab66f4678fad43bce600df9050f..36fa123443a06117b6305d75a3d6b57cf29ed417 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -6348,17 +6348,17 @@ SMI_ACCESSORS(JSGeneratorObject, resume_mode, kResumeModeOffset)
 SMI_ACCESSORS(JSGeneratorObject, continuation, kContinuationOffset)
 ACCESSORS(JSGeneratorObject, operand_stack, FixedArray, kOperandStackOffset)
 
-bool JSGeneratorObject::is_suspended() {
+bool JSGeneratorObject::is_suspended() const {
   DCHECK_LT(kGeneratorExecuting, 0);
   DCHECK_LT(kGeneratorClosed, 0);
   return continuation() >= 0;
 }
 
-bool JSGeneratorObject::is_closed() {
+bool JSGeneratorObject::is_closed() const {
   return continuation() == kGeneratorClosed;
 }
 
-bool JSGeneratorObject::is_executing() {
+bool JSGeneratorObject::is_executing() const {
   return continuation() == kGeneratorExecuting;
 }